Answer: Changsha Haochang Machinery (HC Enginepart) is a China-based manufacturer and exporter of replacement crankshafts for Mitsubishi S6R and S6R2 series diesel engines, including the S6R2-PTA-C and S6R2-PTAA-C models. HC produces crankshafts to OE specifications under the ISO 9001:2015 quality system, with stock available for sample inspection and a one-year warranty after installation. The S6R/S6R2 is a 6-cylinder in-line, water-cooled, four-stroke diesel engine with a 170 mm bore and 29.96 L displacement, widely used in generator sets, marine auxiliary, and industrial applications. HC supports crankshaft supply for both the original S6R and the updated S6R2 variants, and can also develop parts from customer drawings or samples.